检索结果-南通市图书馆

Comprehensive study on the spatial distribution of heavy metals and their environmental risks in high-sulfur coal gangue dumps in China

引用

Journal of Environmental Sciences 2024年第2期136卷 486-497页

作者： Yingbo dong Huan Lu Hai Lin School of Energy and Environmental Engineering University of Science and Technology BeijingBeijing 100083China Beijing Key Laboratory on Resource-oriented Treatment of Industrial Pollutants Beijing 100083China

The accumulation of coal gangue(CG)from coal mining is an important source of heavy metals(HMs)in *** spatial distribution and environment risk assessment are extremely important for the management and remediation of *** soil samples were collected from the high-sulfur CG site in northern China and analyzed for six *** results showed that the soil was heavily contaminated by Mn,Cr and Ni based on the Nemerow index,and posed seriously ecological risk depended on the geo-accumulation index,potential ecological risk index and risk assessment *** semi-variogram model and ordinary kriging interpolation accurately portrayed the spatial distribution of ***,Mn,and Cr were distributed by band diffusion,Ni was distributed by core,the distribution of Cu had obvious patchiness and Zn was more *** spatial autocorrelation indicated that all HMs had strong spatial *** BCR sequential extraction was employed to qualify the geochemical fractions of *** data indicated that Fe and Cr were dominated by residual fraction;Cu,Ni and Zn were dominated by reducible and oxidizable fractions;Mn was dominated by reducible and acid-extractable(25.38%-44.67%)*** correlation analysis showed that pH was the main control factor affecting the non-residue fractions of ***,acid production from high sulfur CG reduced soil pH by 2-3,which indirectly promoted the activity of ***,the conceptual model of HMs contamination at the CG site was proposed,which can be useful for the development of ecological remediation strategies.

关键词： High-sulfur coal gangue Soil contamination Heavy metals Spatial distribution Geochemical fractions Risk assessment

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

On Minor Left Prime Factorization Problem for Multivariate Polynomial Matrices

引用

Journal of Systems Science & Complexity 2024年第3期37卷 1295-1307页

作者： LU dong WANG Dingkang XIAO Fanghui School of Mathematics Southwest Jiaotong UniversityChengdu 610031China KLMM Academy of Mathematics and Systems ScienceChinese Academy of SciencesBeijing 100190China School of Mathematical Sciences University of Chinese Academy of SciencesBeijing 100049China MOE-LCSM School of Mathematics and StatisticsHunan Normal UniversityChangsha 410081China

A new necessary and sufficient condition for the existence of minor left prime factorizations of multivariate polynomial matrices without full row rank is *** key idea is to establish a relationship between a matrix and any of its full row rank *** on the new result,the authors propose an algorithm for factorizing matrices and have implemented it on the computer algebra system *** examples are given to illustrate the effectiveness of the algorithm,and experimental data shows that the algorithm is efficient.

关键词： Free modules Grobner bases minor left prime(MLP) multivariate polynomial matrices polynomial matrix factorizations

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Meta-path reasoning of knowledge graph for commonsense question answering

引用

Frontiers of Computer Science 2024年第1期18卷 49-59页

作者： Miao ZHANG Tingting HE Ming dong National Engineering Research Center for E-Learning Central China Normal UniversityWuhan 430079China Hubei Provincial Key Laboratory of Artificial Intelligence and Smart Learning Central China Normal UniversityWuhan 430079China National Language Resources Monitoring&Research Center for Network Media Central China Normal UniversityWuhan 430079China School of Computer Central China Normal UniversityWuhan 430079China

Commonsense question answering(CQA)requires understanding and reasoning over QA context and related commonsense knowledge,such as a structured Knowledge Graph(KG).Existing studies combine language models and graph neural networks to model ***,traditional knowledge graph are mostly concept-based,ignoring direct path evidence necessary for accurate *** this paper,we propose MRGNN(Meta-path Reasoning Graph Neural Network),a novel model that comprehensively captures sequential semantic information from concepts and *** MRGNN,meta-paths are introduced as direct inference evidence and an original graph neural network is adopted to aggregate features from both concepts and paths *** conduct sufficient experiments on the CommonsenceQA and OpenBookQA datasets,showing the effectiveness of ***,we conduct further ablation experiments and explain the reasoning behavior through the case study.

关键词： question answering knowledge graph graph neural network meta-path reasoning

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Analysis of the Oscillatory Flows of Multiple Shock Waves in a Constant Area Duct

引用

Journal of Thermal Science 2024年第3期33卷 794-806页

作者： K JAMES Jintu KIM Heuy dong Department of Mechanical Engineering Andong National UniversityAndong36729Republic of Korea CAD-IT Korea Co. Ltd.Seoul08591Republic of Korea

The oscillatory response of multiple shock waves to downstream perturbations in a supersonic flow is studied numerically in a rectangular *** shock waves are formed inside the duct at a shock Mach number of *** duct has an exit height of H,and the effect of duct resonance on multiple shock oscillations is investigated by attaching exit ducts of lengths 0H,50H,and *** downstream disturbance frequency varied from 10 Hz to 200 Hz to explore the oscillation characteristics of the multiple shock *** oscillatory response of shock waves under self-excited and forced oscillation conditions are analyzed in terms of wall static pressure,shock train leading-edge location,shock train length,and the size of the separation *** extent of the initial shock location increases with an increase in exit duct length for the self-excited oscillation *** analysis of the shock train leading edge and the spectral analysis of wall static pressure variations are *** variation in the shock train length is analyzed using the pressure ratio method for self-excited as well as forced *** RMS amplitude of the normalized shock train length(ζ_(ST))increases with an increase in the exit duct length for the self-excited oscillation *** the downstream perturbation frequency is increased,ζ_(ST)is decreased for exit duct *** all exit duct designs and downstream forcing frequencies,the size of the separation bubble grows and shrinks during the shock oscillations,demonstrating the dependence on duct resonance and forced oscillations.

关键词： shock train downstream disturbance supersonic flow shock wave boundary layer interaction duct resonance flow separation

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Plasma metabolites and risk of myocardial infarction:a bidirectional Mendelian randomization study

引用

Journal of Geriatric Cardiology 2024年第2期21卷 219-231页

作者： dong-Hua LI Qiang WU Jing-Sheng LAN Shuo CHEN you-Yi HUANG Lan-Jin WU Zhi-Qing QIN Ying HUANG Wan-Zhong HUANG Ting ZENG Xin HAO Hua-Bin SU Qiang SU Department of Cardiovascular Medicine Minzu Hospital of Guangxi Zhuang Autonomous RegionGuangxiChina Senior Department of Cardiology the Sixth Medical CenterChinese PLA General HospitalBeijingChina Library of Graduate School Chinese PLA General HospitalBeijingChina Department of Cardiology Jiangbin Hospital of Guangxi Zhuang Autonomous RegionGuangxiChina Health Management Institute the Second Medical CenterChinese PLA General HospitalBeijingChina

BACKGROUND Myocardial infarction(MI)is a critical cardiovascular event with multifaceted etiology,involving several genetic and environmental *** is essential to understand the function of plasma metabolites in the development of MI and unravel its complex *** This study employed a bidirectional Mendelian randomization(MR)approach to investigate the causal relationships between plasma metabolites and MI *** used genetic instruments as proxies for plasma metabolites and MI and conducted MR analyses in both directions to assess the impact of metabolites on MI risk and vice *** addition,the large-scale genome-wide association studies datasets was used to identify genetic variants associated with plasma metabolite(1400 metabolites)and MI(20,917 individuals with MI and 440,906 individuals without MI)*** variance weighted was the primary method for estimating causal *** estimates are expressed as beta coefficients or odds ratio(OR)with 95%*** We identified 14 plasma metabolites associated with the occurrence of MI(P<0.05),among which 8 plasma metabolites[propionylglycine levels(OR=0.922,95%CI:0.881–0.965,P<0.001),gamma-glutamylglycine levels(OR=0.903,95%CI:0.861–0.948,P<0.001),hexadecanedioate(C16-DC)levels(OR=0.941,95%CI:0.911–0.973,P<0.001),pentose acid levels(OR=0.923,95%CI:0.877–0.972,P=0.002),X-24546 levels(OR=0.936,95%CI:0.902–0.971,P<0.001),glycine levels(OR=0.936,95%CI:0.909–0.964,P<0.001),glycine to serine ratio(OR=0.930,95%CI:0.888–0.974,P=0.002),and mannose to trans-4-hydroxyproline ratio(OR=0.912,95%CI:0.869–0.958,P<0.001)]were correlated with a decreased risk of MI,whereas the remaining 6 plasma metabolites[1-palmitoyl-2-arachidonoyl-GPE(16:0/20:4)levels(OR=1.051,95%CI:1.018–1.084,P=0.002),behenoyl dihydrosphingomyelin(d18:0/22:0)levels(OR=1.076,95%CI:1.027–1.128,P=0.002),1-stearoyl-2-docosahexaenoyl-GPE(18:0/22:6)levels(OR=1.067,95%CI:1.027–1.109,P=0.001),alpha-ketobutyrate levels(OR=1.108,95%

关键词： infarction alterations diagnosis

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A Review on Particle Reinforced Mg Matrix Composites Fabricated by Powder Metallurgy

引用

Acta Metallurgica Sinica(English Letters) 2024年第3期37卷 391-400页

作者： Zhiyuan Liu Li Jin Jian Zeng Fulin Wang Fenghua Wang Shuai dong Jie dong National Engineering Research Center of Light Alloy Net Forming and State Key Laboratory of Metal Matrix Composite School of Materials Science and EngineeringShanghai Jiao Tong UniversityShanghai 200240China

This paper provides a comprehensive review of research progress in particle-reinforced Mg matrix composites prepared via powder *** article discusses different strategies,such as micro-sized,nano-sized particles,and multi-particle hybridization,which has been employed to enhance the performance of the *** addition,a range of preparation techniques that optimize the dispersion of the reinforcing particles are *** paper also highlights how the different configurations between the reinforcements and matrix alloy impact the composites’***,the article outlines the prospects of particles reinforced Mg matrix composites fabricated via powder metallurgy and recommends modification methods that could be explored to further develop these materials for various applications.

关键词： Magnesium matrix composites Reinforcing particle Powder metallurgy Mechanical properties Configuration

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Carbonic anhydrase-like enzymes in the formation of Lycopodium alkaloid

引用

Chinese Journal of Natural Medicines 2024年第3期22卷 193-194页

作者： dong Huiwen GE Huiming State key Laboratory of Pharmaceutical Biotechnology Institute of Functional BiomoleculesSchool of Life SciencesNanjing UniversityNanjing 210023China

Plant alkaloids,renowned for their structural diversity and bioactivity,are prominent in both modern and traditional medicine[1].Unraveling the intricacies of plant alkaloid biosynthesis could pave the way for the discovery of new natural products and *** may also shed light on the roles of existing pathways in host biology and provide valuable tools for metabolic engineering in plants and microbes[2].Unlike other major classes of plant natural products,such as terpenoids and polyketides,the formation of alkaloid scaffolds does not conform to a uniform chemical theme or depend on a singular enzyme class[3].A case in point is the Lycopodium alkaloids in the Lycopodiaceae family,where the enzymes responsible for their core scaffold construction remain unidentified[4].

关键词： Lycopodium alkaloid Carbonic anhydrase-like enzymes Biosynthesis

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Pure State Feedback Switching Control Based on the Online Estimated State for Stochastic Open Quantum Systems

引用

IEEE/CAA Journal of Automatica Sinica 2024年第10期11卷 2166-2178页

作者： Shuang Cong Zhixiang dong Department of Automation University of Science and Technology of ChinaHefei 230027China Lazas Network Technology Co.Ltd Hangzhou 311100China

For the n-qubit stochastic open quantum systems,based on the Lyapunov stability theorem and LaSalle’s invariant set principle,a pure state switching control based on on-line estimated state feedback(short for OQST-SFC)is proposed to realize the state transition the pure state of the target state including eigenstate and superposition *** proposed switching control consists of a constant control and a control law designed based on the Lyapunov method,in which the Lyapunov function is the state distance of the *** constant control is used to drive the system state from an initial state to the convergence domain only containing the target state,and a Lyapunov-based control is used to make the state enter the convergence domain and then continue to converge to the target *** the same time,the continuous weak measurement of quantum system and the quantum state tomography method based on the on-line alternating direction multiplier(QST-OADM)are used to obtain the system information and estimate the quantum state which is used as the input of the quantum system ***,the pure state feedback switching control method based on the on-line estimated state feedback is realized in an n-qubit stochastic open quantum *** complete derivation process of n-qubit QST-OADM algorithm is given;Through strict theoretical proof and analysis,the convergence conditions to ensure any initial state of the quantum system to converge the target pure state are *** proposed control method is applied to a 2-qubit stochastic open quantum system for numerical simulation *** possible different position cases between the initial estimated state and that of the controlled system are studied and discussed,and the performances of the state transition under the corresponding cases are analyzed.

关键词： Online state estimation state feedback control stochastic open quantum systems(OQST) switching control

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

On asymptotic stability of the 3D Boussinesq equations without heat conduction

引用

Science China Mathematics 2024年第2期67卷 253-280页

作者： Lihua dong Yongzhong Sun School of Physical and Mathematical Sciences Nanjing Tech UniversityNanjing 211816China Department of Mathematics Nanjing UniversityNanjing 210093China

We investigate the asymptotic stability of the solutions to Boussinesq equations without heat conduction with the initial data near a specific stationary solution in the three-dimensional domain Ω=R^(2)×(0,1).It is shown that the solution starting from a small perturbation to the stationary solution converges to it with explicit algebraic rates as time tends to infinity.

关键词： Boussinesq equations stationary solutions asymptotic stability decay rates

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Real-time in-situ monitoring of chiral changes during a reaction at single-molecule level

引用

Science China Chemistry 2024年第2期67卷 422-423页

作者： Min Tan dong Xiang Institute of Modern Optics and Center of Single-Molecule Science Tianjin Key Laboratory of Micro-scale Optical Information Science and TechnologyNankai UniversityTianjin300350China School of Materials Science and Engineering Smart Sensing Interdisciplinary Science CenterNankai UniversityTianjin300350China TongLu FeiRan Garment–Nankai University Joint Laboratory Nankai UniversityTianjin300350China

Molecular chirality is a widespread phenomenon in nature,playing a critical role in various fields such as chemistry [1],life sciences [2], and materials science [3], and has therefore attracted significant attention and research by scholars [4–6].However, the chirality in chemical reactions is often dynamic, making real-time monitoring of chiral changes during chemical reactions at the single-molecule level extremely challenging.

关键词： chiral chirality critical

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：